Why don't rooms spontaneously clean themselves up, or scrambled eggs mysteriously unscramble?
CalTech theoretical physicist and author of From Eternity to Here, Sean Carroll, explains the "arrow of time" in physics and its close association with "entropy," a measure of the ever increasing disorder of our universe.
We experience that disorder in our lives as the passage of time, from bumptious to serious to solemn.
In the second half of his IF Conversation, Carroll points out that "what happened before the Big Bang?" is a question that cosmologists increasingly ask. Could it have an answer?